Substances such as medications, contrast media, and local anesthetics have been administered for various clinical situations including implantable pain medication/insulin pumps, interventional radiological and cardiologic procedures, acute perioperative and chronic pain blocks. Historically, such procedures have been performed using a two-man approach. Because of technological limitations, a first person, operating in a sterile field, identified and isolated a patient's structure with a needle or probe. A second person was required to inject the substance from a nonsterile site through a tube into the apparatus held by the first person.
To reduce costs, minimize the potential for problems arising from miscommunication, and reduce manpower requirements, it is desirable for such procedures to be implemented by a single person rather than by two people.